Motor hoist



Feb. 5, 1929,

- J. A. SHEPARD MOTOR HOIST Filed March 25, 1925 2 Sheets-Sheet l xNvx-:NTOR rw BY l #irn 51M ATTORNEY Feb. 5, 1929. 1,701,017

J. A. SHEPARD MOTOR HOI'ST Filed March 25, 1925 2 Sheets-Sheet 2 ATTORNEY Patented Feb. 5, 1929.

UNITED STATES PATENT OFFICE. e

JAMES A. SHEPARD, OF MONTOUR FALLS, NEW YORK, ASSIGNOR TO SHEPARD ELEC- TRIO CRANE & HOIST COMPANY, 0F MONTOUR FALLS, NEW YORK, A CORPORATION OF NEW YORK.

MOTOR HOIST.

Application filed March 25, 1925.

My present invention consists in a motor driven hoist of improved construction, and by the term hoist as used herein I mean to include not only weight lifting devices commonly called hoists, vbut any analogous device, such as a ships winch, which includes a motor rotated winding drum for winding up and paying out a cable, or the like.

`The general object of the present invention is to combine the winding drum of a hoist with the motor for rotating the drum, in a novel manner, characterized by its me chanical simplicity, compactness, effectiveness, and inherently low cost of construction.

In the preferred practical mode of carrying out the invention, I make the winding drum in the form of an annulus which surrounds and is journalled on the outer surthe gear teeth of the winding drum and journalled in the motor frame. Furthermore, I preferably arrange the parts so that the load engaging portion ofthe winding cable extends tangentially away from the portion of the winding drum at the side of the latter at which the gear teeth thereof engage the teeth of the winding drum, and so that a large portion at least, of the pull of the load engaging portion of the cable is transmitted directly to the pinion or pinions directly geared to the winding drum, with the result that'the pull of the cable adds but litttle tothe pressure between the co-operating bearing surfaces of the drum and the motor field ring on which it is journalled, and the frictional resistance to the rotation of the drum is correspondingly small. In one desirable form of the invention, the winding drum is provided with internal gear teeth, the tips of which engage the peripheral bearing surface of the motor field ring which in this case is advantageously specially formed to provide space between it and the winding drum for a driving pinion meshing with the internal gear teeth of the Serial No. 18,122.

winding drum. The invention may be embodied in very different forms however, for example, in another desirable form, the winding drum may be driven by a pinion meshing with gear teeth formed in the peripheral edges of outwardly extending circumferential flanges provided at the ends of the winding drum.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification; but for a better understanding of the in vention, however, its advantages and speciic objects attained with its use, reference should be had tothe accompanying draw ings and descriptive matter in which I have illustrated and described preferred embodiments of my invention.

. Of the drawings:

Fig. l is a side elevation of a hoist;

Fig. 2 is an end elevation;

Fig. 3 is an elevation of the side of the hoist opposite to that shown in Fig. l;

Fig. 4 is a plan view partly in section kon the line 4--4 of Fig. l;

Fig. 5 is a partial section on the line 5-5 of Fig. 4; n

Fig. 6 is a partial section on the line 6-6 of Fig. l;

Fig. 7 is a partial section on the line 7-7 of Fig. 4.

Figs. l to 7 illustrate a traversing hoist embodying a form of the invention. In the construction shown in these figures A represents the field ring of an electric hoist motor provided, as shown, with internal maink poles A', and internal inter-poles A2. Advantageously, as shown, the field ring is provided with internal bosses turnedoff to provide pole seats A3 which are sections of a cylindrical surface co-aXial with the motor armature B. The field ring Ai' has its periphery machined to provide a cylindrical bearing surface A4 for the hoisting drum C. An axially extending recess A5 is formed in the outer surface of the field ring A at oney side, and preferably at the side'at which the hoisting cable D depends. This recess receives an elongated pinion yE which has its teeth in mesh with the internal gear teeth C of the hoisting drum C. The latter is an annular body surrounding the field ring A with the flattened ends of the teeth C bearing on and sliding over the surface At. To provide space for the recess A5 in a iield ring having the proper magnetic circuit proportions, the axis of the `cylindrical lsurface A4 is advantageously displaced horizontally from the axis of the motor armature B, and the field ring body is, in effect, bent around the pinion E.

As shown, the ends of the pinion E turn in ball bearings F and F mounted in open ended bearing chambers Gr, and y', formed in the motor and frames G and g, respectively. 'lhe motor and frames have machined surfaces Which lit against machined end surfaces of the'lield ring A, which is clam aed between and supported by the end frames. At one side of the tield ring, the end frames G and g project beyond the periphery of the hoisting drum C, and are bolted to a cross frame member it, and at the opposite side of the field ring the end frames extend beyond the hoisting drum and are bolted Yto a cross frame member H. The hoist supported by means of hanger yokes I connected to the cross frame members 7i and H, and provided with flanged wheels I running on an overhead track J shown as an l-beam, which may be a. stationary portion of a hoist supporting' structure, or may be carried by an overhead traveling crane according to the conditions of use. The hoist may bo moved longitudinally of the track d manually, or by any usual or suitable power mechanism (not shown) which may be provided for the purpose.

Advantageously, the cross frame member H, which is at the side of the hoisting drum C from which the cable D depends, forms a support for a suitable in otor control mechanism, shown as including an operating lever K, and depending pulls K and K2 for turning the lever K in one direction about its pivotal support to start the armature B into rotation, and in the opposite direction to stop the rotation of the motor.

rPhe motor armature shaft B is j ournalled in the end frame members G and g by means of roller bearings F2 and The roller bearing F2, as shown, is received in an open ended chamber C2 formed in the end frame memberl G, and the roller bearing F is shown as similarly mounted in a bearing chamber g2. Advantageously, and as shown, the bearing chamber g2 is not formed in the body portion of the end frame g, but in a bonnet portion y secured to the member g by bolts g1 and removable to permit the axial withdrawal of the motor armature when necessary without other disturbance to the motor frame. rlhe outer end of the chamber g2 is normally closed by a cap gl0 which assists in supporting a cover g21 made readily removable to permit access to the motor brushes and their supporting mechanism b through apertures in the bonnet gli. The brush holder support b, as shown, is bolted to the motor or to the bonnet 915.

The end of the armature shaft B projecting through the bearing F2 carries a pinion L forming a part of the gearing connecting the motor shaft to the pinion E, aud advantageously, as shown, carries a rotating friction brake disk L co-operating'with nonrotating brake disks M and N which surround the shaft B at the opposite sides of the disk L. The disks M and N are held against rotation by posts O secured to the motor frame G and passing loosely through openings formed for the purpose in portions of the rings M and N which project radially beyond the periphery of they disk L. The friction brake disks L, M, and N are pressed together to thereby arrest the motion of the motor armature by a brake lever P. The latter has a forked lend engaging the disk M and supported by a pivot shaft P supported by brackets P10 carried by the end frame member G. The opposite end of the lever P is advantageously interconnected in a known manner with the control mechanism and the limit switch mechanism, so that when the lever K is turned in one direction to interrupt the supply of energizing current to the motor, the adjacent end of the lever P is moved Outward by the thrust connection P2 and disks L, M, and N thereby pressed together, and so that when the sheave or pulley block D10 connected to the lifting hook D11 approaches the upper limit of its movement, and engages the limit switch actuating member Q, it moves the brake lever thrust rod P2 outward at the same time that it interrupts the supply of current to the motor.. The mechanism by which the brake lever P is thus inter-connected with the lever K, and the limit switch and its actuating mechanism need not be illustrated and described in detail herein, however', as the form of these mechanisms form no part of the present invention, and may be of any known or suitable type.

The` pinion E is rotated by the pinion L through a gear R, which may be secured rigidly to the pinion E, but, as shown, is connected to the pinion E by means permitting a limited movement between the gear R and the pinion E necessary for the operation of an automatic mechanical brake mechanism pre-venting the descent of the load when the motor is cle-energized or overloaded. To this end, the hub of the gear R is internally threaded and screwed onto the threaded end E10 of the pinion E. A nut E on the end of the pinion E limits the movement of the gear R angularly ofthe pinion E in a direction tending to screw the gear ofi' the pinion. spring washer E12 and wear plate R are interposed between the nut E11 and the hub portion of the gear R. The turning movement of the gear R relative to the pinion E in the direction tending to screw the gear onto the pinion is limited by the automatic/brake mechanism.

The latter, in the construction' shown, comprises a hub iiange E20 secured to the pinion E, a floating ring S provided with a projection S at one side received in a pocket G2 in the end member Gr and thereby held against rotation, and a floating annulus T located within the ring S and surrounding hub portions of the iiange E20 and of the gear R. Vhen the gear R turns relative to the pinion E to screw the gear onto the screw portion E10 of the pinion, the iioatin g annulus T is compressed between the gear R and the iange E20. As is usual in friction brakes, the annulus T is provided with the wear plates U at each side, and the adjacent sides of the flange E20 and of the gear it are also'faced with wear plates U, and suitable brake lining material V is interposed between the wear plates of the annulus T and the wear plates on the flange E20 and gear R. A. friction clutch mechanism is provided to prevent the annulus T from turning in the floating ring S with the pinion E in the direction in which the latter turns as the load descends, without interference by this clutch mechanism with the rotation in the opposite direction of the annulus T. The clutch mechanism provided for this purpose comprises rollers T2 received in peripheral pockets T formed in the member T and having their bottoms so inclined that when the member T starts to turn with the pinion E as the load descends, the rollers T2 jam between the inclined bottoms of the pockets T and the inner surface of the ring S and thereby prevent the rotation of the annulus T wit-h the pinion E.

YWith the automatic brake mechanism just described, the reaction of the hoist load tends to effect a rotation of the pinion E relative to the gear R in a direction to cause the screw portion E10 of the pinion to draw the gear R toward the annulus T, and thereby cause the latter to be clamped between the gear and the flange E20, so that when the load is being lifted, the flange E20, annulus T, and gear R all turn together. If' with a suspended load, the energization of the mo tor is interrupted, or is reduced so that the armature torque is less than that required to sustain the load, and the latter starts to descend, its descent is arrested at once by the jamming of the rollers` T2 between the inclined bottoms of the pockets T and the surrounding surface of the non-rotating ring S. To lower the load, the motor armature B must be started into rotation in the proper direction. Since the annulus T can not share in this rotation, the initial eifect is to turn the gear R relative to the threaded portion E10 of the pinion sufficiently to release the clamping pressure on the annulusy T and permit the liange E20 to turn relative to the annulus. The load cannot descend more rapidly than the rotation of the armature B permits, without again clamping the annulus T between the gear and the flange E20. While it is ordinarily desirable to provide a hoist of the character illustrated with some automatic mechanical or dynamic brake mechanism, it is to be understood that the mechanism just described is not a part or necessary to the use of the present invention.

The ends of the cable D are secured as indicated at D to the flanges C2 of the winding drum C, and the central portion of the cable is looped about an equalizing pulley D20 carried by the cross frame member H, the hook sheave D10 being provided with two pulleys, one for each strand of the cable. This arrangement, while not essential, is advantageous, in that the resultant of the load reaction on 'the hoisting drum acts midway between the ends of the latter and does not tend to turnthc latter about a horizontal axis at right angles to the axis of the pinion E.

The bearings F and F, the pinion E, the gear teeth G, and thereby the motor frame bearing surface At, the screw E20 and the automatic brake are lubricated by means of grease cups W and WV. The grease cup W supplies lubricating material to the outer end of the bearing chamber G which is normally closed by a cover to which the grease cup YV is secured. The grease cup VV supplies lubricating material to an axial channel in the pinion E communicating with a radial port'?22 through which lubricating material passes to the outer surface oi the screw E10, and to the automatic brake. The bearing F2 is supplied with lubricating material by a grease cup W0 and a channel TV1 leading from the latter to the outer end of the bearing chamber G2. Lubricating material is supplied to the bearing F0 by means of a grease cup 72 connected to the cover 120 no-rmally closing the end of the bearing chamber g2. The brake mechanisms are covered by a casing G30 secured to the end member Gr and slotted for the passage of the lever P.

With the arrangement shown in Figs. 1 to 7, the pull of the load supporting cable on the winding drum is directly transmitted to and taken by the teeth oi the pinion E., so that the :friction between the field ring bearing surface A? and the iiattened ends of the hoist drum gear teeth C is not appreciably greater wit-h a heavy hoist loadthan when no load is carried by 'the hoist. The hoist,

as a whole, is exceedingly simple in construction, and of relatively low inherent cost of production. The winding drum and the gear connections between it and the armature shaft do not interfere with access to the interior of the motor and particularly to the brushes, or with the removal and displacement of the armature, when this is necessary or desirable.

In addition to the general advantages of the invention just mentioned, the particular construction illustrated in Figs. l to 7 possess certain special advantages. For example, the arrangement permits the gear teeth C on the winding drum and the co-operating teeth on the pinion E to be as long` as the axial length of the hoist drum. This assures a relatively large tooth surface bearing area so that gear tooth wear is minimized by the relatively small pressure per unit of area, between the engaging teeth surfaces, as well as by the facility for good lubrication which the construction provides. The eccentric position of the motor armature B with respect to the outer surface of the iicld ring A makes it readily feasible to provide the eld ring recess A5 to receive the pinion E, without interfering with the magnetic properties of the motor, and without making it diicult to carry out the machining operations necessary to the construction of the motor and the hoist.

lVhile the traversing hoist shown in` Figs. l to 7, inclusive, and hereinbefore described in detail, is a desirable embodiment of my invention, the principle of the invention may well be embodied in quite different 'forms of construction, and be used for different purposes.

Generally speaking, in the construction shown in Figs. l to 7, the nearer the resultant of the pressure between the winding drum gear teeth and the meshing pinion teeth approaches coincidence with the line of action of the cable pull on the drum, the bet-ter. It is to be noted, however, that with the arrangement shown in Figs. l to 7, in which the winding drum gear teeth pitch circle is smaller in diameter than the drum winding` surface, the pull of the cable tends to lift the weight of the winding drum oil' the motor field ring with a corresponding reduction in frictional resistance.

Vhile in accordance with the provisions of the statutes, I have illustrated and described the best embodiments of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

l. The combination with a motor comprising a rotor and a stator surrounding the rotor and provided with a peripheral bearing surface the axis of rotation of which is horizontal and parallel to the rotor axis, of an annular winding drum surrounding said stator and journalled on said surface, said winding drum being provided with a winding surface and with a circumferentially extending set of internal gear teeth located at a distance from the axis of the drum not greatly different from the distance between said axis and the winding surface of the drum, and a driving connection between said rotor and drum including a pinion journalled in the opposite ends of' said stator to turn about an axis parallel to said axes and having its teeth in mesh with said gear teeth.

2. The combination with a motor comprising a rotor and stator surrounding the rotor and provided with a peripheral bearing surface the axis of which is parallel to the rotor axis, of an annular winding drum surrounding said stator and liournalled on said surface and provided with a circumferentially extending set of longitudinally extending internal gear teeth, the pitch diameter of which exceeds the diameter of said bearing surface, and a driving connection between said rotor and drum including a pinion journalled in the opposite ends of said stator to turn about an axis parallel to said axes and having its teeth in mesh with said gear teeth.

3. The combination with an electric motor comprising a rotor and a stator surrounding the rotor and provided with a peripheral bearing surface, of an annular windinor drum surrounding said stator and ournalleLd on said surface and provided with a circumferentially extending set of internal gear teeth, the tips of which engage said bearing surface, a driving connection between said rotor and drum including a pinion journalled in said stator and having its teeth in mesh with said gear teeth and a cable wound about said drum and extending tangentially away from the portion thereof adjacent said pinion, said motor drum and pinion being arranged to rotate about horizontal axes.

el.. An electric hoist comprising a field ring formed with a peripheral bearing surface and a winding drum surrounding said field ring and journalled on said bearing surface for rotation about a longitudinal axis, vertical end frames secured to the ends of said field bearing and forming means for supporting the latter, a bonnet member detachably connected to one of said end frames and an armature mounted in one of said end frames and said bonnet member and arranged for axial withdrawl when said bonnet member' is detached.

5. The combination with a inotorcoinprising a rotor and a stator surrounding the rotor and provided with a peripheral bearing surface, of an annular Winding drum surrounding said stator and having internal gear teeth the tips of which engage said bearing surface, and gearing including a pinion journalled in said stator with its teeth in mesh with the gear teeth of the drum connecting said drum and the rotor.

6. The combination With a motor comprising a rotor and a stator surrounding the rotor and provided With a peripheral bearing surface, of an annular Winding drum surrounding said stator and having internal gear teeth the tips of Which engage said bearing surface, gearing including a pinion journalled in said stator with its teeth in mesh with the gear teeth of the drum connecting said drum and the rotor, and a cable Wound about said drum, and extending tangentially away from the portion thereof adjacent said pinion.

7. The combination With a motor comprising a rotor and a stator surrounding the rotor and provided with a peripheral bearing surface, of an annular Winding` drum surrounding said stator and having internal `gear teeth the tips of which engage said bearing surface, said stator being formed With a peripheral recess, a pinion ournalled in said stator with its body portion received in said recess and With its teeth in mesh with the gear teeth of the drum, and gearing connecting' said pinion to the rotor.

S. The combination With a motor comprising a rotor and a stator surrounding the rotor and provided with a peripheral bearing surface, of an annular Winding drum surrounding` said stator and having internal gear teeth the tips of Which engage said bearing surface..` said stator being formed with peripheral recess, a pinion journalled in said stator 'with its axis in the same horizontal plane the axis of the drum and With its teeth in mesh with the gear teeth of the drum, gearing connecting said pinion to the rotor, and a cable Wound about said drum, and depending tangentially away from the portion thereof adjacent said pinion.

9. An electric hoist comprising in combination a motor ield ring having a cylindrical outer surface With a peripheral recess therein at one side of the motor axis, end frame members detachably secured to the ends of said field ring, a hoisting drum in the form of an annular body surrounding said field ring and formed With internal axially eX- tending gear teeth the tips of which bear against said surface, a pinion journalled at its ends in. said end frames and having its body located in said field ring recess audits teeth in mesh* with the teeth of said hoisting drum,y a motor armature journalled in said end frames to turn about an axis laterally displaced from the axis of said surface away from said recess, and gearing connecting iid armature to said pinion.

l0. in electric hoist comprising in combination a motor lield ring` having a cylindrical outer surface, with a peripheral recess therein at one side of the motor axis, end frame members detachably secured to the ends of said field ring and extending laterally away from the latter at opposite sides thereof, cross frame members to which the laterally extening portions of the end frame members are connected, Wheeled suspension members connected to said cross frame member, a hoisting' drum in the form of an annular body with internal axially extending gear teeth surrounding said field ring With the tips of said gear teeth bearing against the peripheral surface of the latter, a pinion journalled at its ends in said end frames and having its body located in said iield ring recess and its teeth in mesh with the teeth of said hoisting drum, a motor armature journalled in said end frames, and gearing connected to said pinion, and a hoisting cable connected to said Winding frame and depending from the latter at the side thereof adjacent said pinion.

1l. ln an electric hoist, a hoist motor cornprising a field ring having an external cylindrical Winding drum bearin surface With an axially extending depression in said surface and provided with internal pole pieces defining an armature space the axis of which is laterally displaced from the axis of said cylindrical surface in a direction away from said recess.

12. In an electric hoist, a hoist motor coinprising a field ring havingan external cylindrical Winding drum bearing surface with an axially extending depression in said surface and provided. with internal pole seats forming parts of a cylindrical surface the axis of which is laterally displaced from the axis of said cylindrical bearing surface in a direction away from said recess.

13. In an electric hoist, a hoist motor comprising a iield ring` having an external cylindrical Winding drum bearing surface with an axially extending recess in said surface and with seats for motor end frames, said seats being circular about an axis laterally displaced from the axis of said surface in a direction away from said recess, and motor end frames mounted in said seats provided with armature bearings coaxial with said seats.

14. ln an electric hoist, a hoist motor cornprising a vfield ringhaving an external cylindrical Winding' drum bearing surface With an axially extending recess in said surface and with seats for motor end frames, said said field ring and symmerically disposed about the armature axis.

Signed at Montour Falls, in the county 10 of Schuyler and State of New York, this 18th day of March A. D. 1925.

JAMES A. SHEPARD. 

